The urgent need for an effective man portable blast shield for bomb disposal personnel has escalated in recent time because of an increased use of improvised explosive devices. Various means have been used in the prior art to provide personal protective armor to those involved in bomb disposal work. However, the problem with these prior art devices was that they were primarily designed to protect against fragmentation with little or no consideration given to bodily injury resulting from blast pressure effects. The National Bomb Data Center of Picatinny Arsenal, Dover, N.J., in General Information Bulletin 73-2 dated Apr. 6, 1974 states that ear injuries may occur from blast pressures as low as 0.03 pounds per square inch and lung damage from blast pressures as low as 30 psi. With regard to lung injury, the Bulletin states:
"It is necessary for the blast shock wave to strike the chest in order to cause lung injury. Injuries occur primarily as a result of the pressure wave acting directly on the chest wall, and not normally from the pressure passing into the lungs through the air passageways. When the blast shock wave strikes the body, the chest wall is hurled violently inward and blood and other body fluids are driven into portions of the lungs which normally contain only air, thus causing hemorrhaging. PA1 "Additionally, when the chest wall moves inward with such high velocity, the air pressure in the lungs will exceed the normal air pressure outside the body. When this occurs, the inward moving chest wall stops and is then hurled violently outward. These movements, and the speeds at which they occur, rupture the lung tissues and air is forced into the fluid carrying portions of the lungs. The degree of lung injury is therefore related to both the velocity and the amount of chest wall movement, which in turn are determined by the amount of blast pressure striking the chest wall."
The present invention is effective in substantially reducing the probability of blast pressure shock wave ear and lung injury to bomb disposal personnel. The present invention utilizes a rigid, hard, smooth shell to enclose the body air spaces in a manner that will cause a blast shock wave to travel around the outside of the shell as it passes.